1. Department of Cardiology; University General Hospital of Larissa; Larissa Greece
2. Department of Cardiovascular Medicine; Heart and Vascular Institute, Kaufman Center for Heart Failure, Cleveland Clinic; Cleveland OH USA
3. Independent Biostatistician; Athens Greece
4. First Cardiology Department; University General Hospital AHEPA; Thessaloniki Greece
5. Department of Quantitative Health Sciences; Cleveland Clinic; Cleveland OH USA
6. Department of Cardiology; Athens University Hospital Attikon; Athens Greece